Tag: Germany

Grassland butterflies: important indicators of the state of nature

With the Grassland Butterfly Index for Germany, UFZ scientists are providing important input for the implementation of the EU Nature Restoration Regulation.

One of the goals of the EU Nature Restoration Regulation, which came into force in 2024, is to halt species loss and preserve important ecosystem services provided by agricultural landscapes.

Scientists at the Helmholtz Centre for Environmental Research (UFZ), in collaboration with the Senckenberg German Entomological Institute (SDEI), have now calculated the Grassland Butterfly Index for Germany – an indicator of the state of biodiversity proposed in the EU regulation.

The results, published in the open-access journal Nature Conservation, show a negative trend, especially in recent years. For their calculations, the researchers were able to draw on 4 million observation data collected at the UFZ over the last 20 years as part of the ‘Butterfly Monitoring Germany’ programme.

Orange butterfly on a leaf.
Small Copper (Lycaena phlaeas), a species for which the index shows a positive trend.
©Werner Messerschmid.

Agricultural landscapes are among the most degraded habitats worldwide. Their restoration is one of the key measures for halting global biodiversity loss and preserving important ecosystem services.

“The Nature Restoration Regulation (NRR), which came into force in 2024, is an essential instrument for achieving the restoration targets set for the European Union,” says Prof. Josef Settele, agroecologist at the UFZ. The objectives also include increasing biodiversity in agricultural ecosystems (Article 11 of the NRR), taking into account climate change, the needs of rural areas and sustainable agricultural production. To implement the overall objectives, EU Member States are required to develop national restoration plans and implement concrete measures in terrestrial, freshwater, coastal and marine habitats.

The extent to which the specific measures are effective and the ecosystems develop positively will be determined using indicators. For agricultural landscapes, these are (a) the grassland butterfly index, (b) the stock of organic carbon in cropland mineral soils, and (c) the share of agricultural land with high diversity landscape features. For at least two of these three indicators, the EU regulation calls for an upward trend towards a satisfactory level by 2030. Since natural conditions vary across EU countries and there is a wide range of different land management practices, Josef Settele argues that all EU countries should start by recording all three indicators so that none of them is prematurely dropped.

With the ‘Grassland Butterfly Index’, a research team led by the UFZ has now calculated one of the three indicators for Germany for the first time and published the results in the journal Nature Conservation. The data for this analysis comes from Butterfly Monitoring Germany (Tagfalter-Monitoring Deutschland – TMD), a long-term programme coordinated by the UFZ and the Society for Butterfly Conservation (GfS). Every week during the summer, volunteers count butterflies at fixed locations using a standardised European method.

“Since the TMD was launched in 2005, this has resulted in around four million data records being collected, which provide information on the development of butterfly populations in Germany,” explains one of the co-authors of the publication, biologist Elisabeth Kühn, who coordinates the German Butterfly Monitoring programme at the UFZ.

What does the index show for Germany?

The ‘Grassland Butterfly Index’ tracks the development of populations of 15 butterfly species from 2006 to 2023 that are considered typical inhabitants of various grassland biotopes.

Of the 15 indicator species, four are increasing (green), five are declining (red) and no significant trend could be identified for six species (grey). ©UFZ.

“Four species have increased, five species show a declining trend. For six species, the trend is uncertain, which is probably due to insufficient data and large differences between the locations where they were found,” says the study’s lead author, bioinformatician Alexander Harpke. In the first decade of the period analysed (2006 to 2016), the index for Germany as a whole shows a slightly positive trend – which does not rule out the possibility that this may vary greatly for individual species.

However, if we look only at recent years (2016 to 2023), the index shows a significant decline overall. This mainly affects specialised species such as the Small Blue (Cupido minimus) or the Dingy Skipper (Erynnis tages); generalists such as the Small Copper (Lycaena phlaeas) or the Meadow Brown (Maniola jurtina) are hardly affected.

These results show that the trend for grassland butterflies in Germany during the comparison period corresponds to the trend at European level, which was last determined by Butterfly Conservation Europe in 2025 for all 27 member states.

A brown butterfly.
Dingy Skipper (Erynnis tages), a species that declined in Germany between 2006 and 2023. ©Erk Dallmeyer.

Butterflies as indicators

Butterflies are known to be sensitive to changes in their environment. Land use plays a decisive role in this. “The loss and fragmentation of habitats have a proven negative effect on the long-term survival of butterfly populations. Intensive mowing, nitrogen inputs and pesticides contribute to a deterioration in habitat quality or increased mortality. Species that depend on specific habitats, such as nutrient-poor grasslands, also suffer from a lack of use, e.g. through grazing or mowing,” explains Prof. Thomas Schmitt from the Senckenberg German Entomological Institute (SDEI) in Müncheberg, who is also co-author of the study.

In addition to land use, climate change is increasingly contributing to changes in butterfly fauna. Higher temperatures favour the spread of heat-loving or tolerant species, while species adapted to cooler conditions are in decline.

These dependencies of butterflies on land use and climate change make them excellent indicators of the state of our ecosystems. In addition, they are easy to record – especially by qualified volunteers. Together, these two factors have provided an invaluable database for butterfly monitoring in Germany, which scientists are now evaluating to calculate trends and indicators for reporting under European environmental legislation.

“The significance and representativeness of the indicator could be further increased if government programmes such as Habitats Directive monitoring or nationwide insect monitoring were integrated into the analysis,” says UFZ biologist and co-author of the publication Dr Martin Musche. The same would apply if data from neighbouring countries were included.

The work on this publication was funded by the UFZ and the GfS, as well as by the National Monitoring Centre for Biodiversity and the Federal Agency for Nature Conservation (BfN) as part of the FAMos project, with funds from the Federal Ministry for the Environment, Climate Protection, Nature Conservation and Nuclear Safety (BMUKN).


Publication:

Harpke A, Kühn E, Schmitt T, Settele J, Musche M (2025) The Grassland Butterfly Index for Germany. Nature Conservation 59: 315–334. https://doi.org/10.3897/natureconservation.59.162812

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North American turtles establish succcessful populations in Germany, possibly threathening ecosystems

For the first time, self-sustaining populations of three non-native species of turtles were identified in south-western Germany by researchers at the University of Freiburg

For the first time, self-sustaining populations of three non-native species of turtles were identified in south-western Germany by researchers at the University of Freiburg

Original text published by the University of Freiburg

Three species of turtles native to North America have been successfully reproducing in the wild in Germany, report for the first time environmental researcher Benno Tietz and biologist Dr. Johannes Penner of the University of Freiburg, along with Dr. Melita Vamberger of the Senckenberg Natural History Collection in Dresden.

Their results were published in the open-access scientific journal NeoBiota.

The scientists examined a total of nearly 200 animals living in the wild in lakes in Freiburg and Kehl. Their findings suggest that the turtles have established themselves in a new habitat, where they could become a threat to the local ecosystem.

For two species, this is the first evidence of independent reproduction outside of their natural reproductive range. For the third species, this is the northernmost evidence of its presence up to now,

says Penner.
The false map turtle (Graptemys pseudogeographica) enjoys the sun’s warmth. Photo: Johannes Penner.

Turtles released into the wild

Invasive species do a great deal of economic damage world-wide. They also contribute to advancing global species extinctions.

Alien reptiles regularly make their way into the wild in Germany. Most often, this is because they have been released by pet owners.

Large numbers of North American pond sliders (Trachemys scripta) were imported into the European Union (EU) in the 1980s and 1990s as house pets. In 1997, their import into the EU was banned. By 2016, the sale of specimens born here was also made illegal.  Since then, pet shops have replaced them with other freshwater turtles, such as the river cooter (Pseudemys concinna) and the false map turtle (Graptemys pseudogeographica).

Genetic analyses of specimens of all three species in a range of ages have now demonstrated that they are reproducing independently in local waters. 

What’s surprising is that the invasive species have established themselves so far north. In Europe, successful reproduction and self-maintaining populations of Trachemys scripta were only known in the Mediterranean regions and the continental climate zone of Slovenia,

explains Benno Tietz.

Until recently, it had been assumed the turtles being examined couldn’t reproduce in Central Europe due to the colder climate. Especially the false map turtle is actually quite sensitive to the cold,

he says.
A North American pond slider (Trachemys scripta) resting on a lily pad. Photo: Johannes Penner.

Consequences for local species unclear

The invasive turtles could become a problem for indigenous species.

The European pond turtle (Emys orbicularis), for example, is now only present in Germany in parts of Brandenburg.

In an experimental setup, the European pond turtle showed weight loss and an increased death rate when being kept together with Trachemys scripta,

reports Penner.

Penner says that could be caused by the larger, alien species forcing the smaller local turtles from places where they sun themselves, leading the local turtles to have  problems with thermoregulation. Or perhaps the competition led to them having greater challenges when seeking food. 

Beyond that, aquatic turtles could be hosts for viruses and parasites, leading them to play a role in the spread of diseases. This could potentially have a damaging influence on other parts of the ecosystem, including amphibians, fish, or aquatic plants.

On the other hand, in their study, the researchers consider the alien species could assume functions in damaged ecosystems that would otherwise go unreplaced.

Vamberger says these questions urgently need to be explored further.

We need to raise public awareness that people should not release – no matter what kind of species – any animals into the wild in future.”

she insists.
A river cooter (Pseudemys concinna) lets itself drift in the water. Photo: Johannes Penner.
Meet the research team:

Dr. Johannes Penner was the scientific coordinator of the research training group “Conservation of Forest Biodiversity in Multiple-Use Landscapes of Central Europe” (ConFoBi) and a lecturer for the Chair of Wildlife Ecology and Management of the University of Freiburg. Currently, he is a curator at the NGO “Frogs and Friends” and a guest researcher in wild animal ecology.

Benno Tietz has completed a Master’s degree in Environmental Sciences at the University of Freiburg. His thesis – finished in the Winter Semester of 2020/2021 – investigated alien turtles. Currently, he is a research assistant at the Freiburg Institute of Applied Animal Ecology.

Dr. Melita Vamberger is a researcher at the Senckenberg Natural History Collection in Dresden.

***

The study was supported by the Hans Schimenz Fund of the German Society for Herpetology and Terrarium Science (DGHT) as well as the Academic Society of Freiburg.

***

Research paper:

Tietz B, Penner J, Vamberger M (2023) Chelonian challenge: three alien species from North America are moving their reproductive boundaries in Central Europe. NeoBiota 82: 1-21. https://doi.org/10.3897/neobiota.82.87264

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Efficiency of insect biodiversity monitoring via Malaise trap samples and DNA barcoding

The massive decline of over 75% insect biomass reported from Germany between 1989 and 2013 by expert citizen scientists proves the urgent need for new methods and standards for fast and wide-scale biodiversity assessments. If we cannot understand species composition, as well as their diversity patterns and reasons behind them, we will fail not only to predict changes, but also to take timely and adequate measures before species go extinct.

An international team of scientists belonging to the largest and connected DNA barcoding initiatives (iBOL, GBOL, BFB), evaluated the use of DNA barcode analysis applied to large samples collected with Malaise traps as a method to rapidly assess the arthropod fauna at two sites in Germany between May and September.

One Malaise trap (tent-like structure designed to catch flying insects by attracting them to its walls and then funneling them into a collecting bottle) was set in Germany’s largest terrestrial protected natural reserve Nationalpark Bayerischer Wald in Bavaria. Located in southeast Germany, from a habitat perspective, the park is basically a natural forest. The second trap was set up in western Germany adjacent to the Middle River Rhine Valley, located some 485 kilometers away from the first location. Here, the vegetation is eradicated annually due to St. Martin’s fires, which occur every November. Their findings are published in the open access Biodiversity Data Journal.

DNA barcoding enables the identification of a collected specimen by comparing its BIN (Barcode Index Number) against the BOLD database. In contrast to evaluation using traditional morphological approaches, this method takes significantly less experience, time and effort, so that science can easily save up on decades of professional work.

However, having analyzed DNA barcodes for 37,274 specimens equal to 5,301 different BINs (i.e., species hypotheses), the entomologists managed to assign unambiguous species names to 35% of the BINs, which pointed to the biggest problem with DNA barcoding for large-scale insect inventories today, namely insufficient coverage of DNA barcodes for Diptera (flies and gnats) and Hymenoptera (bees and wasps) and allied groups. As the coverage of the reference database for butterflies and beetles is good, the authors showcase how efficient the workflow for the semi-automated identification of large sample sizes to species and genus level could be.

In conclusion, the scientists note that DNA barcoding approaches applied to large-scale samplings collected with Malaise traps could help in providing crucial knowledge of the insect biodiversity and its dynamics. They also invite their fellow entomologists to take part and help filling the gaps in the reference library. The authors also welcome taxonomic experts to make use of the unidentified specimens they collected in the study, but also point out that taxonomic decisions based on BIN membership need to be made within a comparative context, “ideally including morphological data and also additional, independent genetic markers”. Otherwise, the grounds for the decision have to be clearly indicated.

The study is conducted as part of the collaborative Global Malaise Trap Program (GMTP), which involves more than 30 international partners. The aim is to provide an overview of arthropod diversity by coupling the large-scale deployment of Malaise traps with the use of specimen-based DNA barcoding to assess species diversity.

Sequence analyses were partially defrayed by funding from the government of Canada through Genome Canada and the Ontario Genomics Institute in support of the International Barcode of Life project. The German Barcode of Life project (GBOL) is generously supported by a grant from the German Federal Ministry of Education and Research (FKZ 01LI1101 and 01LI1501) and the Barcoding Fauna Bavarica project (BFB) was supported by a 10-year grant from the Bavarian Ministry of Education, Culture, Research and Art.

 

 

Original source:

Geiger M, Moriniere J, Hausmann A, Haszprunar G, Wägele W, Hebert P, Rulik B (2016) Testing the Global Malaise Trap Program – How well does the current barcode reference library identify flying insects in Germany? Biodiversity Data Journal 4: e10671. https://doi.org/10.3897/BDJ.4.e10671

Underwater mushrooms: Curious lake fungi under every turned over stone

While fungi are well known for being essential in cycling carbon and nutrients, there are only about 100,000 described species in contrast to the 1.5 to 3 millions, assumed to exist on Earth. Of these, barely 3000 fungi belong to aquatic habitats. In fact, freshwater fungi have been researched so little, it is only now that an international research team provide the first lake-wide fungal diversity estimate in the open access journal MycoKeys.

Over the spring and the early summer of 2010, a large team of scientists, led by Dr Christian Wurzbacher and Dr Norman Warthmann, affiliated with the Leibniz-Institute of Freshwater Ecology and Inland Fisheries and the Berlin Center for Genomics in Biodiversity Research, Germany (currently at University of Gothenburg, Sweden, and the Australian National University, Australia, respectively), collected a total of 216 samples from 54 locations, encompassing eight different habitats within Lake Stechlin in North-East Germany.image-1

Having recovered samples on three occasions over the course of the study, their aim was to test how habitat specificity affects the fungal community and whether fungal groups would reflect the availability of particulate organic matter as substrate. Unlike previous studies of aquatic fungi that compared water samples among different lakes or seasons, theirs would compare the diversity among habitats within a single lake. This included the study of fungi living in the water and the sediments, as well as fungi living on the surfaces of plants and other animals.

As a result, the scientists concluded that every type of habitat, i.e. sediments, biofilms, and submerged macrophytes (large aquatic plants), has a specific fungal community that varies more than initially expected. Of these, lake biofilms, representing a group of microorganisms, whose cells stick to each other, and cling together to a surface, turned out to be the hotspots for aquatic fungi.

“Our study provides the first estimate of lake-wide fungal diversity and highlights the important contribution of habitat heterogeneity to overall diversity and community composition,” the scientists summarise. “Habitat diversity should be considered in any sampling strategy aiming to assess the fungal diversity of a water body.”

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Original source:

Wurzbacher C, Warthmann N, Bourne EC, Attermeyer K, Allgaier M, Powell JR, Detering H, Mbedi S, Grossart H-P, Monaghan MT (2016) High habitat-specificity in fungal communities in oligo-mesotrophic, temperate Lake Stechlin (North-East Germany). MycoKeys 16: 17-44. https://doi.org/10.3897/mycokeys.16.9646

Cost-benefit analysis of strategies against severely harmful giant hogweed in Germany

While invasive species are considered to be a primary driver of biodiversity loss across the globe, species such as the alien for Germany giant hogweed pose even greater risks, including health hazards to humans, limited accessibility to sites, trails and amenity areas, as well as ecological damages.

Since 1st January 2015, EU member states are obligated to develop concrete action plans against (further) spread of invasive alien species. In order to do so, however, policymakers need adequate knowledge about data of the current spread situation as well as information about costs and benefits of control measures. Therefore, German researchers analyse the present situation and control measures, as well as the cost-effectiveness of the possible eradication strategies. Their analysis is published in the open access journal NeoBiota.

Largely spread across Germany, the giant hogweed (H. mantegazzianum) grows in a wide range of habitats, including roadsides, grasslands, riparian habitats and woodland margins. The highest invasion percentage (18.5%) was found for abandoned grasslands, field and grassland margins, and tall-forb stands.

While the species poses a serious threat on native biodiversity through competitive displacement of native plants, it is particularly dangerous to human health. Its watery sap contains several chemical agents. In contact with the skin, this sap can cause severe blistering if the person is simultaneously exposed to sunlight. Furthermore, the hypersensitivity of the skin towards sunlight may persist for a number of years. Additionally, the giant hogweed can limit public accessibility to sites, trails and amenity areas, as well as inflict ecological damages, such as erosion at riverbanks.

In order to provide policymakers with the information needed for adequate control measures, Dr. Sandra Rajmis from the Julius Kühn-Institute, Dr. Jan Thiele from the University of Münster, and Prof. Dr. Rainer Marggraf from Georg-August-Universität Göttingen examine costs and benefits of controlling giant hogweed in Germany.

To address these challenges, the scientists firstly study the present state and costs of control measures, based on survey data received from German nature authorities. Then, they analyse the identified control options in terms of cost effectiveness with regard to the invaded area types and sizes in the infested German districts. To estimate the benefits of the eradication strategies, they turn to a choice experiment survey conducted in German households.

“Only in light of these findings, policymakers can properly understand about the societal costs and benefits of alternatives and decide about societal favored control options in Germany,” point out the researchers.

The team also notes that cost-effectiveness of eradication strategies depends on the length of the period over which they are implemented and observed.

“As this is the first cost-benefit analysis estimating welfare effects and societal importance of giant hogweed invasion control, it could serve as guideline for assessments of eradication control in other European countries and support the implementation of the EU directive 1143/2014,” they conclude.

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Original source: Rajmis S, Thiele J, Marggraf R (2016) A cost-benefit analysis of controlling giant hogweed (Heracleum mantegazzianum) in Germany using a choice experiment approach.NeoBiota 31: 19-41. doi: 10.3897/neobiota.31.8103